Many devices have been developed for improving the mixing of fuel and air and increasing the efficiency of a four-cycle multiple cylinder internal combustion engine. Such devices typically include shaped passages within the intake manifold and various atomizing devices and the like which are specifically adapted to be interposed between a carburetor base and the intake manifold of such an engine to increase the turbulence of the fuel-air mixture flowing therethrough. Typically, these atomizing devices are relatively easily connected to an existing engine system by simply unbolting the carburetor and fitting the device onto the top of the intake manifold.
A recurring problem encountered in efforts to improve the operation of the multiple cylinder four-cycle internal combustion engine is the nonuniform distribution of fuel and air to the respective cylinders of the engine. Many intake manifolds, and particularly those used on relatively elongated engines, such as an inline six cylinder engine having a single carburetor, have intake manifolds which are curved particularly in the passages that lead to the cylinders most remote from the carburetor. As fuel-air mixture flows through the remote cylinder passages and around the curves of the manifold, separation of the fuel from the air may result whereby certain of the cylinders will run relatively rich, that is; having a high quantity of fuel relative to air, and certain of the cylinders will run relatively lean, that is; having a relatively high quantity of air to fuel.
Normally, these engines are tuned to obtain proper operating conditions in the lean cylinders to prevent knocking or predetonation by adjusting the mixture needle valve of the carburetor so that the cylinders which would be lean without further adjustment are correct and thereby creating even richer conditions in the remaining cylinders. Accordingly, these rich running cylinders excessively consume fuel, have incomplete combustion with attendant emission of certain pollutants and cause the build-up of carbon in those cylinders which can result in burned valves and the like.
Moreover, another inherent problem in the operation of four-cycle multicylinder internal combustion engines lies in the pulses of the intake manifold. Whereby the fuel-air mixture reciprocates somewhat within the carburetor mixing chamber, particularly at low engine speeds, resulting in the addition of extra fuel to the fuel-air mixture. Commonly, restrictions are placed between the cylinders and the carburetor to reduce blow back but typically these only marginally perform because to eliminate blow back using these prior art restrictions, excessive restriction of the intake manifold would be required and would result in poor engine performance.
In view of the above, the principal objects of the present invention are: to provide a fuel-air mixture regulator for improving the operating and performance characteristics of a multiple cylinder four-cycle internal combustion engine by reducing the effects of the above mentioned defficiencies; to provide such a regulator wherein a port opening varies in response to differential pressure on a reed or valve member overlying same to improve the mixing of fuel and air supplied to the engine cylinders; to provide such a regulator having a variable port to increase turbulence and improve the atomization and vaporization of fuel in the air and thereby result in more efficient operation of the engine; to provide such a regulator which does not excessively restrict the intake manifold of the engine so as to decrease the performance characteristics thereof; to provide such a regulator which will increase the velocity and turbulence of the fuel-air mixture to improve the operating efficiency of the engine and decrease the rate of fuel consumption; to provide such a regulator which will result in a more complete burning of the combustion mixture and thereby reduce emission of certain pollutants; to provide such a regulator which will increase and tend to maintain the uniformity of the fuel-air mixture distributed to each of the cylinders of the engine and provide smooth and efficient operation; to provide such a regulator which can be easily installed on existing conventional multicylinder four-cycle internal combustion engines without substantial alterations to existing engine structure; and to provide such a regulator which is economical to manufacture, has a minimum number of parts, is positive in operation and easy to maintain and that is particularly well adapted for its intended use.